The long-range goal of this proposal is to examine the effects of adolescent-alcohol drinking experience on the brain reward system. The hypothesis of the present proposal is that neuroadaptations in the brain's reward systems occur during adolescent alcohol drinking, increasing behavioral and neurobiological sensitivity to alcohol in adulthood. Operant techniques will first be used to examine alcohol-seeking behaviors, determining differences in the amount of work subjects are willing to perform for reward. Then, intracranial self-administration (ICSA) and microinjection-microdialysis techniques will be used illuminate effects on reward within the mesolimbic dopamine system. Adolescent male and female rats from the selectively bred alcohol-preferring P line will be used because they readily demonstrate an operant sensitivity to the rewarding effects of alcohol after peri-adolescent exposure. The overall purpose of this research is to improve the current understanding of the neurobiological mechanisms underlying the increased sensitivity to alcohol present after adolescent alcohol drinking experience, which may contribute to risk for alcoholism. [unreadable] [unreadable] [unreadable]